print job popup

Hi,
In my enterprise we have several domains.
The majority of the domains are linked throught WINS and DNS. The problem is when a guy in domain X sends a print job, sometimes a popup occures on the desktop of another guy with the same user name at domain Y. There is a way to block that NETBIOS info. to go from one domain to another ? (All WS and SVR are WIN NT and the only protocol used is TCP/IP).

Thanks